Improvement in electric telephones



W F. COOK, I Electric-Telephones;

PatntedSept. 9,1879.

" WIZ'NESSES:

gum If '7 INVEA T Ok A :1 T ORNE KS:

UNITED STATEs PATENT WILLIAM F. 0001;, on IVY MILLS, PENNSYLVANIA.

IMPROVEMENT IN ELECTRIC TELEPHONES.

Specification forming part of Letters Patent No. 219,446. dated September 9, 1879; application filed Julie 4, 1879,

i To all whom it may concern:

Be it known that I, WILLIAM F. 000K, of

V Ivy Mills, in the county of Delaware and State of Pennsylyania, have invented certain new and useful Improvements in Electric Telephones and I'do hereby declare the tollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in,

the art to which it pertains to make and use it, reference being had to the accompanying drawing, which forms part of this specification, in which the figure is a longitudinal vertical section of my invention.

My invention is based on the fact that it two a or more suitable bodies be so juxtaposed in an electric circuit that one of them may be mechanically vibrated with reference to the other, .a variation in the electric current sent over such circuit and through such bodies will be produced in its passage from one to the other when soundwaves are thrown upon a dia phragm in contact with such vibratory body, whereby such sound -waves may be transmitted over such circuit or made audible in like means at a receiving-station.

a My invention accordingly consists in the Q novel construction, as hereinafter described and claimed, of a telephonic instrumentor telerent in its passage between two juxtaposed bodies of suitable material placed in such circuit, onejof said bodies being so constructed and arranged that it may be mechanically vibrated with reference to the other, such vibratory body being in contact with a metallic diaphragm. p i

In carrying my invention into effect, I construct a telephone as follows: I takea suitable case or shell of any appropriate materiali wood, for exam,pleprovided with a trumpet shaped mouth-piece.

Within this case, and close to the inner opening of said mouth-piece, I locate a metallic diaphragm, the outer edges of which are firmly fixed in position,' while its center is free to vibrate under the influence of carbon or gas-coke, D.

a spring-arm, whose other end is fastened to the side of the case or to a projection therefrom.

Attached to said spring, on the inner side or opposite thcwulcaiiite button, is a button of position with this button is another button or block of similar material, which is titted in a sleeve, so that it may be adjusted to and from the button to which it is juxtaposed by means of a screw and sprin Both these buttons are, by suitable connections, placed in an electric circuit, so that an electric current passing over such circuit will pass through both and from one to the other. An instrument of this description is placed at either end of an lelectrical circuit, and electrical connection established by means of a battery or equivalent.

Now, if sound-waves be thrown upon the diaphragm of one of these instruments, they will be reproduced upon the other diaphragm, and articulate speech be thus received and made audible over an electric circuit without the employment of a magnet, induction-coil,

or chemical compound.

Referring to the accompanying drawing, A

indicates a shell or case of any suitable mate said spring opposite the diaphragm. The but ton U is necessarily made of vulcanite, but

may be of any form or materiah'and may even be a part of the spring itself or a part of button D.

Gris a bridge, of wood or other non-conducting material, sustained on pins or screws 9 g, and having a tubular opening or sleeve, G,

In contact or juxta 0 represents a button, of vulca iitc or which forms an annular guide for a carbon block or button, or a mass of equivalent mapass through openings in the plate h, and are surrounded by spiral springs z" 11, which bear against said plate h and the bridge Gr. By these means the button H is adjusted in the direction of the button D by the screw K, and in the contrary direction by the springs t" z". The buttons D and H arein juxtapositiointhe former having liberty of mechanical vibration toward and from the button H, or between the latter and the diaphragm O.

L and M are binding-posts, and l m wires leading therefrom to the metal spring E and plate I, as shown. From these respective posts wires 1 and m extend to form electrical connection with another like instrument at any suitable distance, a battery or equivalent generator being duly connected in the usual or any suitable manner.

Speech or other audible sound-waves delivered on the diaphragm of one of these instruments when the electrical connection is established will be transmitted to and received and reproduced by the diaphragm of the other in strument in audible tones.

What I claim as my invention is- The instrument herein described, consisting of a case, A, with mouth-piece B, diaphragm 0. spring sustained button D, and I rigidly-supported button H, with spring and screw adjustments, substantially as shown and described.

In testimony that I claim the foregoing I 

